Portable electronic devices such as smartphones or tablet PCs may access wireless communication networks as they include antennas for transmitting and receiving wireless signals.
The antennas may transmit and receive signals of frequency bands ranging from a band of several hundred MHz to a band of several GHz to connect to a wireless communication network such as a cellular network. The antennas, for example, may be disposed inside and/or outside the electronic device.
Because the antennas mounted on the electronic device are mounted in the limited interior spaces of the electronic devices, the antennas may be arranged very close to each other. For example, when adjacent antennas transmit and receive signals of neighboring (or the same) frequencies, signals may interfere with each other. This may lower the overall performance of the antennas, for example, may deteriorate isolation characteristics. Moreover, when the housing of the electronic device is formed of a conductive material (e.g., a metal), the radiation performance of the antenna may be further lowered.